Spent some time pulling together calibration numbers for AS, REFL and POP diodes, and makeing a total power budget.
Bottom line:
- The missing 20% power (8Watts!) is not coming out of any port, and thus must be absorbed in the interferometer.
- The way to distinguish loss in the recycling cavity and (280 times smaller) loss in the arms is to look at the sideband recycling gains.
Attached is a plot of power at each port, plus the power in the recycling cavity cast into cumulative arm loss (by multiplying with 279 power buildup and 95ppm round trip losses). Note that there is virtually no increase in AS power, and even a decrease in REFL power. the 8 missing Watts are absorbed in the interferometer.
Note that it is very difficult to distinguish arm losses from PRC losses using the carrier. However the two cenarios are very different for the sidebands - for arm losses both sideband hardly see anything. However, for PRC losses, the 9MHz sideband responds quickest, since it starts off with a hight recycling gain. The 2nd attached plot illustrats this. My money is on PRC losses.
The signals I picked for calibration are:
'H1:LSC-REFL_A_LF_OUTPUT':
0.1*0.5^3*(1-800e-6)^3*1000 = 12.47 mWatt REFL (=cts) / Watt from IFO
10% beam spplitter
two 50% beam splitter
three 800ppm loss mirrors
50% beam splitter
1000mW/W
'H1:LSC-POP_A_LF_OUTPUT':
229e-6*0.1*1e6 = 22.9 uWatt POP (=cts) / Watt in PRC
229 ppm of PR2
10% beam splitter
1e6uW/W
'H1:ASC-AS_C_SUM_OUTPUT':
0.965*800e-6*0.48*0.8*997*10^(36/20)*1638.4 = 3.0554e+04 cts / Watt from SRM
0.965 Faraday transmission
800ppm transmission mirror
48% beam splitter
0.8 Quantum Efficiency
997 Ohm transimpedance
36dB whitening gain
1638.4 cts/V ADC
Note: This calibration has the most estimate factors in it. I don't rust it better than ~25%.
'H1:OMC-DCPD_A_OUTPUT' & 'H1:OMC-DCPD_B_OUTPUT':
0.965*(1-800e-6)^2*0.99*0.93*0.5*0.85817*0.9*1000 = 343 mA / Watt carrier 00 mode from SRM
0.965 Faraday transmission
two 800ppm loss mirrors
1% loss mirrir
93% OMC transmission
50% splitter
0.85817 A/Watt ideal
90% Quantum Efficiency (is this right?)
1000mA/A
